.round-img-box{
    width: 100%;
    height: 100%;
    position: relative;
    overflow: hidden;
}
.round-img-item {
    width: auto;
    height: 100%;

    display: none;
    margin: 0 auto;
    vertical-align: middle;

}

.round-img-item.show {
    display: block;
}
.round-img-play-bar{
    position: absolute;
    width: 100%;
    height: 42px;
    background-color: rgba(0,0,0,0.5);

}
.round-img-play-btn{
    position: absolute;
    width: 20px;
    height: 20px;
    background-color: transparent;
    box-sizing: border-box;

    left: 50%;
    top:50%;
    margin-left: -10px;
    margin-top: -10px;
    border-left:20px solid #fff;
    border-bottom: 10px solid transparent;
    border-top: 10px solid transparent;
    border-right: 10px solid transparent;
}
.round-img-play-btn.r-i-p{
    border: 10px solid #fff;

}